Blueberry Pest Mystery Solved by NC State Scientists

Scientists at N.C. State University have pinpointed the longhorn beetle as the cause of a decade-long mystery plaguing blueberry bushes in Southeastern North Carolina. Since its first observation around 2010, the pest has baffled farmers and researchers, impacting a valuable crop worth nearly $105 million in 2023. The beetle's larvae consume blueberry roots, leading to a slow die-off of the plants.

Identifying the specific species, Prionus imbricornis, was challenging due to the larvae's hidden location and the similarity to other longhorn beetle larvae. Researchers employed genetic sampling, comparing larvae DNA to adult beetles trapped from farms in New Hanover, Pender, Sampson, and Bladen counties. This investigation, detailed in a June 2026 publication in the Journal of Integrated Pest Management, marks North Carolina as the first state to report this beetle actively feeding on blueberries.

With no existing insecticides labeled for this pest in blueberries, researchers are now conducting trials to find effective treatments that do not harm beneficial insects. They are also studying the optimal timing for applications, as damage is caused by the larvae. A key question remains why this beetle species has shifted its diet from stressed hardwood trees to blueberry bushes, with climate change-induced stress on the plants being a leading theory.